Clutch Release Question

NeedSpace · NeedSpace's Garage

I may have screwed up. I purchased this clutch release for my 1976 (number 6).

I now know that this was made for the 915/40,43,45,48. Here's my question, can I use this on my 915/61 or should I bit the bullet and buy the right pieces?

BTW, this is why I shouldn't have purchased pieces before doing all my research!

Flat6pac · 12-13-2011, 04:30 AM

That should be the right one for the 76 if you have the exhaust crossover pipe like on the 75 and SCs. It moves the cable around so the adjustment end doesnt hit the cross pipe.
More important, the cable needs to match the arm you use for proper length.
Bruce

Walt Fricke · 12-14-2011, 08:16 PM

Bruce - you have finally solved something which has always bothered me - why did Porsche come up with that cable breaker, 90 degree bend system? But my '77 (now SC) has always had the early exhaust (now SSI), so no crossover pipe.

I did adapt one of these to work with the simpler style arm with a V notch (or, for that matter, a U notch) with a V fitting. I took a piece of rectangular steel tube of suitable dimensions, slid it over the end of this arm, drilled holes so the cable end (the shorter kind, used on the simpler arm) would pass through by the groove meant to bend the cable around. The forward hole was larger so the rod end wouldn't bind on it as the angles changed. I welded a small bolt onto the tube so I could attach it to the hole already there in the arm. And I welded a piece across the open end of the tube to make sure things wouldn't collapse. It worked fine for several years until I rounded up the kind I wanted.

Having a cable which is too long is better than having one which is too short. When I end up buying a cable which is too long, I just slip a piece of steel tubing over the excess threaded rod after it is through the V block, and then put on the locking nuts.

On a car which has been worked over for many years, using the factory parts book to get the "right" parts doesn't always work.

But Needspace, how did you come to need this part in the first place? This February I had this arm fall off! But it was on the Sebring race track during a race, and it is kind of bumpy, and going back to look for it was out of the question. No one of my acquaintance has ever known of this happening, but it did to me.

NeedSpace · NeedSpace's Garage

Thanks for both of your responses.

Basically, I acquired the car for VERY LITTLE money but it did not come with a tranny or engine. I now have an engine (a 2.7) and a transmission (915). The transmission did not come with the clutch release arms or the various springs I see in many pics (lucky me). Here is a photo of my transmission (915/61 717)

Before connecting the transmission to the engine, I did a dry run fit under the tube to get a feel for how it all goes together (and any parts I may be missing). In this shot, it appears this is a more modern 915 as it has a separate pin for the spring. Again, based on my research so please clarify where I am off. That said, I have a 76 2.7 transmission with exhaust, and honestly, I don't know what exhaust it is so I am not sure if the clutch release arm I have will fit or not. My plan, get it all together and see how it all fits.

WALT- if you have any pics of you clutch connections, I would be eager to see them. I want to try to get my 911 as original as possible (not looking for a frankenporsche), but that said, I want it to work with out breaking my wallet. I have hoping to have it all working and together for less than $4500...so far, on track.

NeedSpace · NeedSpace's Garage

Thanks for both of your responses.

Basically, I acquired the car for VERY LITTLE money but it did not come with a tranny or engine. I now have an engine (a 2.7) and a transmission (915). The transmission did not come with the clutch release arms or the various springs I see in many pics (lucky me). Here is a photo of my transmission (915/61 717)

Before connecting the transmission to the engine, I did a dry run fit under the tube to get a feel for how it all goes together (and any parts I may be missing). In this shot, it appears this is a more modern 915 as it has a separate pin for the spring. I suppose I could get rid of the extra pin and replace the fork shaft. That said, I have a 76 2.7 transmission with exhaust, and honestly, I don't know what exhaust it is so I am not sure if the clutch release arm I have will fit or not. My plan, get it all together and see how it all fits, then purchase the other bits. But I am interested in hearing what others might recommend. I have only installed engines 3 times and never on a porsche (and never on a car that was missing so many pieces).

WALT- if you have any pics of you clutch connections, I would be eager to see them. I want to try to get my 911 as original as possible (not looking for a frankenporsche), but that said, I want it to work with out breaking my wallet. I have hoping to have it all working and together for less than $4500...so far, on track.

Walt Fricke · 12-15-2011, 11:27 PM

You have the spring assisted type of clutch release system. You need the harp spring, the long arm which attaches to the harp, and the splined short arm with an adjustment screw, as well as a circlip or two.

A parts diagram for this setup will be obvious, and will show part numbers and anything I have missed. You need the clutch cable with the forged eye end.

The arm you purchased (or at least showed a parts diagram of) won't work. To make it work you would have to acquire a different style of vertical splined shaft. You would also have to adapt the piece on the transmission which holds the end of the clutch cable, though that is fairly simple to do. But not worth it - the harp spring makes the clutch action work more easily.

NeedSpace · NeedSpace's Garage

So after a little research, it appears that my transmission is a 1977 to 1979 transmission. I was debating simply switching the throw out fork shaft for the smaller one for the 76 as I already have the proper clutch release lever, but I am thinking this might not be the best way to go. Any thoughts from others?

I might bite the bullet and purchase all the bits. Looks like all in it'll be about $300-400, but I'll be better served doing it right. Also, as the engine still needs to go in, I can shop around for the parts a little.

The one big wildcard is will the exhaust pipes give proper clearance for my plan?

Another smaller concern is that it may be difficult to find all the pieces. Looks like I'll need 13, 15-21, 24

Walt Fricke · 12-16-2011, 08:23 PM

Bruce has all this figured out much better than I do, but you should not have crossover pipe issues since the SCs all have those while in factory trim. I think I had to dimple my nice new SSI's heater box a little when I finally rusted out my '74 exhausts.

Porsche dismantlers and 915 transmission repair shops would be a good source for the bigger parts like the long and short levers (13 and 18 in the diagram). If post 14 doesn't come with your long lever, I'd buy that new. I'd buy a new harp spring, as they tend to break but don't fall apart into two pieces, so you don't realize it except the clutch action is much harder. The adjusting bolt and lock nut come from your nut and bolt can. The little bits you can afford to buy new, I wager. But any old spring will do for 24. Pin 15 can be a roll pin from a hardware store - take the lever in to get one which fits. It doesn't have any force on it other than the weight of the long arm.

Oh - get a proper sized circlip to hold the short arm on.

Pictures of my kludges are on a non-functioning computer at the moment, and a bit of a pain to access. The way you are heading doesn't involve kludges, which isn't a bad thing.